1. Field
The described technology relates generally to a rechargeable battery and a method for manufacturing the same
2. Description of the Related Art
A rechargeable battery can be repeatedly charged and discharged, unlike a primary battery. A low-capacity rechargeable battery may be used for a small portable electronic device such as a mobile phone, a laptop computer, and a camcorder. A large-capacity rechargeable battery may be used as a power supply for driving a motor of a hybrid vehicle and the like.
For example, a rechargeable battery includes an electrode assembly provided with electrodes on both surfaces of a separator, a case receiving the electrode assembly, a cap plate coupled with an opening of the case, and electrode terminals installed on the cap plate and connected to the electrodes through lead tabs.
The electrode terminal, for instance, includes a rivet part disposed in a terminal hole of the cap plate and a terminal plate disposed on an outer surface of the cap plate. The rivet part and the lead tab are electrically connected to each other inside the cap plate. The rivet part and the terminal plate are electrically connected to each other outside the cap plate.
An inner end of the rivet part is made of the same material as the lead tab inside the cap plate and an outer end of the rivet part is made of the same material as the terminal plate outside the cap plate. In other words, the inner and outer ends of the rivet part are formed of different materials at the terminal plate side and the lead tab side, and bonded to the terminal plate and the lead tab.
Accordingly, the number of processes for fabricating and assembling the electrode terminal increases, which causes an increase in a fabrication cost of the electrode terminal. For instance, when the lead tab connected to a negative electrode and the terminal plate are respectively made of copper (Cu) and aluminum (Al), the rivet part has the inner end made of copper (Cu) and the outer end made of aluminum (Al).
The outer end made of aluminum of the rivet part connected to the negative electrode may be contacted with an electrolytic solution inside the rechargeable battery due to a sealing defect in the terminal hole of the cap plate. In this case, the outer end of the rivet part may be melted due to an electrochemical reaction in the negative electrode.
The above information disclosed in this Background section is only for enhancement of understanding of the background of the described technology and therefore it may contain information that does not form the prior art that is already known in this country to a person of ordinary skill in the art.